The present invention relates to an electronic payment process using a smart card.
It is known that electronic means already exist for carrying out certain transactions, such as e.g. the payment for goods, the payment for telephone communications or various services. This is undergoing rapid development, because it offers considerable advantages as regards speed, ease and security. It is possible to refer in this connection to "electronic money".
These means use a smart card, which is a plastic support in which is embedded an electronic component containing a microprocessor, which contains a data memory of several hundred bits produced in Eprom technology. It consists of an Electrically Programmable Read-Only Memory.
The electronic processing performed in such a card consists of making a payment unit or token correspond with each bit of a memory zone. A point of sale terminal equipped with a card reader performs a transaction by lacing a certain number of bits in the memory. The lacing of a bit consists of electrically passing a bit in the memory which was in logic state 1 corresponding to the crediting of one unit to logic state 0 corresponding to zero credit. As this data memory is produced in Eprom technology, this change of state is electrically irreversible.
These smart or chip cards have been described as with respect to their operation and applications in an article by Michel Ugon and Louis Guillou entitled "les cartes apuce" published in "La Recherche", no. 176, April 1986, vol. 17, pp. 472-479.
Although satisfactory in certain respects, these electronic payment processes suffer from disadvantages. Thus, on the one hand it is not possible to reload the card and on the other hand there is a high bit consumption, the number of laced bits being in fact equal to the number of tokens to be debited.